Ubuntu
linux package

  1. Bug #428910
  2. Comment #7

Comment 7 for bug 428910

Revision history for this message
Roman Yepishev (rye) wrote :

Dear Stefan,

Thanks for your time investigating this bug!

So, I added acpi_backlight=vendor string to the kernel cmdline and backlight controls DO work now contrary to what gets printed to dmesg:
[ 461.856388] ACPI: Failed to switch the brightness
[ 463.473236] ACPI: Failed to switch the brightness

I see that /sys/platform/acer-wmi/backlight/acer-wmi/brightness is present and reflects the current state properly.

I will try building the kernel with the patch you posted and see what happens.

Regarding date: yes, it is a proper date, lshal - power_management.acpi.linux.version = '20090521' , so it is definitely an unitialized memory.

Thanks again!